Automated apparatus for feeding and positioning strips in machines for making rectangular frames

Description

[0001] The industrial production of wood frame-like structures, and particularly of rectangular frames for paintings, photographs, mirrors and other items, already uses automated systems and machines which, starting from four strips with both ends cut at 45°, pick them and place them between four stapling units which are meant to rigidly couple them, at the four corners of the frame, by virtue of appropriate steel staples to be inserted pneumatically astride the joint lines. Furthermore, by virtue of a system of electronically controlled motorized carriages, the mutual position of the stapling units is adapted in each instance to the dimensions of the frames being produced.

[0002] The facts summarized above are illustrated and described in detail in EPA No. 00107060.6, in the name of the same Applicant as the present invention, which also provides for the use of particular devices that, after picking the four strips from one or more conveyors, by virtue of appropriate translational motions and rotations, would deposit them so as to compose the frame at the four stapling units.

[0003] The subsequent practical testing of this machine has allowed to ascertain practically the validity and efficiency of the individual devices and of their combination as well as the high quality level of production. However, careful analysis of the various steps of operation has revealed the need and the possibility to further increase the competitiveness of the machine, significantly increasing hourly production, which is currently penalized by a strip feeding system which is not adequate for the operating speed of the stapling units with which the machine is provided.

[0004] Moreover, in the meantime the need has also been felt to complete certain frames, during the assembly of the strips and therefore before joining them by means of the staples, by inserting a transparent plate or a panel of any kind in the appropriately slotted inner edge or, vice versa, by snugly inserting the inner edge of the strips in a corresponding perimetric slot of the panel to be framed.

[0005] An automated apparatus for feeding and positioning strips in machines, according to the preamble of claim 1, is known from FR 2 674 789A.

[0006] Accordingly, the aim of the present invention is to provide an automated apparatus which, in addition to significantly reducing the time required to position the strips to be joined and the time required to adapt the machine to changes (even frequent ones) in the format of the frames to be assembled, allows the arrival of all the strips on a single side of the machine, so that any panels or sheets to be combined with the strips can be fed on the opposite side, thus achieving the removal of the finished products from one of the two sides that are perpendicular to the ones used for the two mutually opposite feeds.

[0007] Furthermore, since the strips arrive from the cropping unit to the machine in parallel rows and on the same side, this gives an advantage to the strip conveyance system, because it can pick them up from a single cropping unit and because the apparatus can itself be constituted by multiple lines in parallel.

[0008] The above aim and other objects, which will become better apparent hereinafter, are achieved with an apparatus according to claim 1. An apparatus according to the invention is advantageously but not exclusively fed, as shown in Figure 11, by a conveyor which picks the strips prepared by a conventional cropping unit and conveys them toward an apparatus in accordance to the present invention.

[0009] The accompanying drawings clearly show that the strips L, which exit from the cropping unit G and are conveyed by the belt S, pass first on the two-track belt U and then continue on the four-track belt V, which conveys them to the four belts W which act as buffer storage, since each one is long enough to contain at least two strips in a row, and move when the downstream machine requests the strips with which the frame is to be formed in each instance.

[0010] By examining Figure 17 in greater detail it can be noted that the strips standing by on the four buffer belts W are sorted so that there are two short ones in each one of the two intermediate belts and two long ones in each one of the two outer belts. This sorted arrangement is provided by three flaps P: one is arranged above the belt U (Figure 18) and two are arranged above the belt V (Figure 19), and said flaps are pivoted vertically to arms which cantilever out onto said belts and are actuated by a corresponding number of actuators Q so that each one can sort the strips in two adjacent tracks.

[0011] Obviously, the actuators Q are controlled by an electronic system which, in addition to discriminating the length and the number of the strips, controls the actuation sequence of the flaps P according to the tracks to be fed.

[0012] The apparatus according to the present invention, combined with the above described conveyor, is described hereinafter with the aid of ten drawings which show merely by way of non-limitative example:

Figures 1 and 2, which are a perspective view and a plan view of the apparatus according to the present invention;

Figures 3 and 4 are two different perspective views of the assembly of the carriages and of the corresponding guides for moving the strips, according to the present invention;

Figures 5 and 6, which are two perspective views of the right carriage of the central movement unit;

Figures 7 and 8, which are two different perspective views of the left carriage of the central movement unit;

Figures 9 and 10 are two different perspective views of the single carriage of the transverse movement unit located to the right of the central one;

Figures 11 and 12, which are two different perspective views of the single carriage of the transverse movement unit located to the left of the central one;

Figures 13 and 14 schematically illustrate the feeder means by showing, from above, only the strip movement units and the conveyor belts that feed them;

Figures 15 and 16 are a simplified top view and bottom view of the set of carriages with the corresponding guides which illustrate one of the possible embodiments of the apparatus illustrated in the preceding figures;

Figures 17-18-19 illustrate one of the possible ways of conveying the strips from a conventional type of cropping unit to an apparatus provided according to the present industrial patent.

[0013] A first summary examination of the accompanying drawings, particularly of the general views of Figures 1 and 2, shows first of all that the apparatus is constituted by a frame T on which four stapling units (F1-F2-F3-F4) of the machine that forms rectangular frames are mounted; the stapling units are surmounted by a feeding system, also mounted on the frame T, which is provided with four carriages (A-B-C-D) which pick up a corresponding number of strips (L1-L2-L3-L4) from respective conveyor belts (N1-N2-N3-N4), fed in any manner, and then deposit them in the underlying stapling units, forming the frame.

[0014] For the sake of simplicity in description, the apparatus comprises a movement system (Figures 3 and 4) which is composed of three units: a central movement unit, which nonlimitatively includes the two carriages A and B and a horizontal beam X, in the opposite vertical faces of which the corresponding pairs of sliding guides 1 for the sliders of the carriages are provided; a right transverse movement unit, which nonlimitatively includes the carriage C and a horizontal beam Y which has, on a vertical face, a pair of sliding guides 1 for the sliders of the carriage; a left transverse movement unit, which nonlimitatively includes the carriage D and a horizontal beam Z which has, in a vertical face, the pair of sliding guides 1 for the sliders of the carriage.

[0015] Figures 3 and 4, and the Figures 5-12 , show that each one of the four carriages (A-B-C-D), in addition to being provided with sliders 2 to be engaged in appropriate sliding guides 1, is stably connected to a toothed belt 3 which is stretched between two pulleys, of which one is keyed or in any case rigidly coupled to the shaft of an electric gearmotor M which is controlled electronically, and produces the linear translational motion of the carriage in both directions.

[0016] Furthermore, a pneumatic cylinder 4 is vertically supported in a horizontal flat portion of each one of the four carriages and its stem 5 protrudes downward, ending with a horizontal arm 6 provided with a pneumatic clamp 7 by virtue of which one of the strips L1-L2-L3-L4 can be gripped centrally.

[0017] By virtue of a guide 10, which is fixed to the pneumatic cylinder 4 so that a rod 9 connected to a stem 5 by virtue of a connecting element 8 can slide therein, the stem 5 and the cylinder 4 are mutually rigidly coupled both when, as for the carriage C, the arm 6 of the clamp 7 does not have to perform any rotation and deposits the strip L3 (Figure 14) with the same orientation with which it picked it up (Figure 13), and when, as in the example of Figures 13 and 14, each one of the strips L1-L2-L4 requires a particular individual rotation.

[0018] Accordingly, while the strip L3 conveyed by the carriage C is subjected only to a linear translational motion, the remaining three strips, before being deposited on the stapling units, must also be rotated as follows: the strip L1 of the carriage A must be rotated clockwise through 90°; the strip L2 of the carriage B must be rotated counterclockwise through 90°; and the strip L4 of the carriage D must be rotated clockwise through 180°.

[0019] In the carriages A-B-D, in order to achieve these rotations, the pneumatic cylinder 4 is rotationally supported by means of a bearing and is coaxially rigidly coupled to one of the two pulleys that stretch a toothed belt 11 on which an appropriately provided pneumatic cylinder 12 acts in a linear fashion alternately in one direction and the other.

[0020] It should be noted that when some carriages, such as A and B, have to pick up strips such as L1 and L2 which arrive on belts N1 and N2 arranged parallel to a transfer direction of the carriages (Figure 13), the clamps 7 of the carriages (Figures 5-8) are mounted so that the clamped strips are parallel to the arms 6 of the clamps. Otherwise, when carriages, such as C and D, must pick up strips, such as L3 and L4, which arrive on belts N3 and N4 which are perpendicular to the transfer direction of the carriages, the clamps 7 of the carriages (Figures 5-8) are mounted so that the clamped strips are perpendicular to the arms of the clamps.

[0021] As exemplified in Figures 15 and 16, the strip L4, either because it has already been turned through 180° or because of any other reason, might arrive on the conveyor belt N4 with an orientation which is opposite to the orientation of the remaining strips L1-L2-L3. In such circumstances, the left transverse movement unit, i.e., the unit of the beam Z, might use a carriage E which is mirror-symmetrically identical to the carriage C also in the orientation of the clamp 7, since like the carriage it is preset for the simple linear translational motion of the conveyed strip.

[0022] With reference to Figures 13 and 14, the conveyor belts N1-N2-N3-N4 convey the four strips to the respective pick-up regions formed by corresponding abutments R, which can be adjusted, according to the length of the individual strips, so that the pick-up clamps 7 of the carriages can grip them exactly at the center.

[0023] However, the abutments R of the belts N1 and N2 might also be fixed, since the carriages A and B, by moving in the same direction as the belts, can still be arranged at a center of the respective strips L1 and L2 regardless of their length.

[0024] It is noted that the three movement units, i.e., the central one and the two transverse ones, operate simultaneously and are synchronized so as to avoid collisions among the strips. This occurs also by virtue of the fact that the length of the stems 5 of the pneumatic cylinders 4 can allow, if necessary, to stagger the height of the strips so that they are transferred and/or rotated at different heights.

[0025] However, the arms 6, which protrude horizontally from the stems 5 and space the clamps 7 away from the stems, in addition to avoiding interference among the devices, especially in the production of small frames, also act as a shear joint in order to avoid worse damage in case of collisions due to any malfunction.

[0026] From the above description it is evident that once the strip L4 has been turned through 180° as shown in Figure 15 and once the strips L1 and L2 have been turned through 90° clockwise and counterclockwise respectively, by actuating the four gearmotors M that move the belts 3 for advancing the four carriages A, B, C, D, the strips are arranged adjacent to each other until their ends, chamfered at 45°, mutually abut. Then the stapling units F1-F4 insert the staples in the joints of the strips; by joining the strips, said staples form the frame (see Figure 14).

[0027] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

Claims

1. An automated apparatus for feeding and positioning strips in machines for making rectangular frames, which machine is equipped with four stapling units for joining, by means of steel staples, the strips (L1-L4) that form the frames, characterized in that the apparatus is equipped with corresponding conveyor belts (N1-N4) and four motorized carriages (A-B-C-D) which are provided with rotating arms fitted with clamps (7) for gripping the individual strips and move on respective guides, which are parallel to the conveyor belts that feed the strips for a first couple of the carriages (A,B) and are perpendicular to said conveyor belts for a second couple of the carriages (C,D), wherein the strips are picked from the conveyor belts (N1-N4) and are transferred and positioned correctly in the stapling units by the four motorized carriages (A-B-C-D).

2. The apparatus according to claim 1, characterized in that the carriages (A-B-C-D) are provided with sliders (2) to engage each carriage (A) slidingly in a pair of sliding guides (1), the pair of guides for a first one of the carriages and a pair of guides for a second one (B) of the carriages being each located in one of two opposite vertical faces of a horizontal beam (X) which lies parallel to the conveyor belts of the strips and at right angles to further beams (Y,Z), in a vertical face of which the pair of sliding guides (1) in which a third one (C) and a fourth one (D) of the carriages are to be engaged respectively is located.

3. The apparatus according to claim 2, characterized in that each one of the four carriages (A-B-C-D) is connected to a toothed belt (3) which is stretched between two pulleys, one of said pulleys being coupled to a shaft of an electric gearmotor (N), and determines a linear translational motion of the carriage in both directions.

4. The apparatus according to claim 3, characterized in that a pneumatic cylinder (4) is vertically supported in each one of the four carriages (A-B-C-D), a stem (5) of the cylinder protruding downward and ending with a horizontal arm (6) which is provided with a clamp (7) for gripping centrally one of the strips for forming the frame.

5. The apparatus according to claim 4, characterized in that a guide (10) is fixed to the pneumatic cylinder (4) and a rod (9) connected to the stem (5) by a connecting element (8) can slide therein, said stem (5) and the cylinder (4) being mutually rigidly coupled.

6. The apparatus according to claim 5, characterized in that the pneumatic cylinder (4) is rotationally supported by a bearing and is coaxially rigidly coupled to one of the two pulleys that stretch a toothed belt (11) on which a cylinder (12) acts in a linear fashion in alternating directions.

7. The apparatus according to claim 6, characterized in that a further carriage (E) is provided which is mirror-symmetrically identical to the one of the carriages (A-D).

8. The apparatus according to claim 1, characterized in that the conveyor belts (N1-N4) convey the four strips (L1-L2-L3-L4) up to the respective pick-up regions formed by corresponding abutments (R) which are adjusted according to the length of the individual strips and so that the pick-up clamps (7) of the carriages (A-B-C-D) can grip said strips exactly at the center.

9. The apparatus according to claim 8, characterized in that the abutments (R) of a first one (N1) and a second one (N2) of the belts (N1,N2) are fixed.

10. The apparatus according to claim 4, characterized in that said carriages and said clamps are controlled by an electronic computer.

Ansprüche

1. Automatische Vorrichtung zum Zuführen und Positionieren von Leisten in einer Maschine zur Herstellung rechteckiger Rahmen, wobei die Maschine mit vier Hefteinheiten ausgestattet ist, die dazu dienen, mittels Stahlheftklammern die Leisten (L1 - L4) zusammenzufügen, welche die Rahmen bilden,
dadurch gekennzeichnet,
daß die Vorrichtung mit entsprechenden Förderbändern (N1 - N4) und vier motorisierten Trägereinrichtungen (A-B-C-D) ausgestattet ist, welche mit Dreharmen versehen sind, die mit Klemmen (7) zum Greifen der einzelnen Leisten verbunden sind, und welche auf entsprechenden Führungen beweglich sind, die für ein erstes Paar Trägereinrichtungen (A, B) parallel zu den die Leisten zuführenden Förderbändern und für ein zweites Paar Trägereinrichtungen (C, D) senkrecht zu den Förderbändern verlaufen, wobei die Leisten aus den Förderbändern (N1 - N4) mittels der vier motorisierten Trägereinrichtungen (A-B-C-D) entnommen sowie ordnungsgemäß an die Hefteinheiten übergeben werden

2. Vorrichtung nach Anspruch 1,
dadurch gekennzeichnet,
daß die Trägereinrichtungen (A-B-C-D) mit Schiebern (2) versehen sind, um jede Trägereimrichtung (A) verschieblich mit einem Paar Schiebeführungen (1) zusammengreifen zu lassen, wobei sich das Paar Führungen für die erste der Trägereinrichtungen und das Paar Führungen für die zweite (B) der Trägereinrichtungen jeweils in einer der zwei gegenüberliegenden, senkrechten Fläche eines Horizontalträgers (X) befinden, welcher parallel zu den Förderbändern für die Leisten und rechtwinklig zu weiteren Trägern (Y, Z) liegt, wobei sich in je einer von deren vertikalen Flächen ein Paar Schiebeführungen (1) befindet, in welche eine dritte (C) bzw. eine vierte (D) der Trägereinrichtungen eingreifen kann.

3. Vorrichtung nach Anspruch 2,
dadurch gekennzeichnet,
daß jede der vier Trägereinrichtungen (A-B-C-D) mit einem Zahnriemen (3) verbunden ist, welcher zwischen zwei Riemenscheiben gespannt ist, wobei eine der Riemenscheiben mit der Welle eines elektrischen Getriebemotors (N) gekoppelt ist, und welcher eine lineare Translationsbewegung der Trägereinrichtung in beide Richtungen vorgibt.

4. Vorrichtung nach Anspruch 3,
dadurch gekennzeichnet,
daß ein Pneumatikzylinder (4) in jeder der vier Trägereinrichtungen (A-B-C-D) vertikal gelagert ist, wobei eine Stange (5) des Zylinders nach untern vorsteht und mit einem horizontalen Arm (6) endet, welcher mit einer Klemme (7) zum mittigen Greifen einer der Leisten zur Ausbildung des Rahmens versehen ist.

5. Vorrichtung nach Anspruch 4,
dadurch gekennzeichnet,
daß am Pneumatikzylinder (4) eine Führung (10) befestigt ist und darin ein Stab (9), der mit der Stange (5) über ein Verbindungselement (8) verbunden ist, verschieblich ist, wobei die Stange (5) und der Zylinder (4) starr miteinander gekoppelt sind.

6. Vorrichtung nach Anspruch 5,
dadurch gekennzeichnet,
daß der Pneumatikzylinder (4) drehbar durch ein Lager gelagert und koaxial starr mit einer der Riemenscheiben gekoppelt ist, die einen Zahnriemen (11) spannen, auf den ein Zylinder (12) in linearer Weise in wechselnder Richtung einwirkt.

7. Vorrichtung nach Anspruch 6,
dadurch gekennzeichnet,
daß eine weitere Trägereinrichtung (E) vorgesehen ist, die spiegelsymmetrisch zu den Trägereinrichtungen (A-D) identisch ist.

8. Vorrichtung nach Anspruch 1,
dadurch gekennzeichnet,
daß die Förderbänder (N1-N4) die vier Leisten (L1-L2-L3-L4) bis zu entsprechenden Entnahmebereichen zuführen, welche durch entsprechende Anschläge (R) gebildet werden, die entsprechend der Länge der einzelnen Leisten einzustellen und so ausgebildet sind, daß die Entnahmeklemmen (7) der Trägereinrichtungen (A-B-C-D) die Leisten exakt in der Mitte greifen können.

9. Vorrichtung nach Anspruch 8,
dadurch gekennzeichnet,
daß die Anschläge (R) des ersten (N1) und des zweiten (N2) der Bänder (N1, N2) fixiert sind.

10. Vorrichtung nach Anspruch 4,
dadurch gekennzeichnet,
daß die Trägereinrichtungen und die Klemmen durch einen Elektronikrechner gesteuert werden.

Revendications

1. Appareil automatisé pour l'alimentation et la mise en position de bandes dans des machines pour réaliser des cadres rectangulaires, laquelle machine est équipée de quatre unités d'agrafage pour joindre, aux moyens d'agrafes en acier, les bandes (L1-L4) pour former les cadres,
caractérisé en ce que l'appareil est équipé avec des courroies de convoyage correspondantes (N1-N4) et quatre chariots motorisés (A-B-C-D) qui sont pourvus de bras rotatifs pourvu de pinces (7) pour saisir les bandes individuelles et les déplacer sur des guides respectifs, qui sont parallèles aux courroies de convoyage qui alimentent en bandes un premier couple des chariots (A, B) ;
et sont perpendiculaires aux dites courroies de convoyage pour un second couple de chariots (C, D), tandis que les bandes sont prélevées des courroies de convoyage (N1-N4) et sont transférées et positionnées de manière correcte dans les unités d'agrafage par les quatre chariots motorisés (A-B-C-D).

2. Appareil selon la revendication 1, caractérisé en ce que les chariots (A-B-C-D) sont pourvus de glissières (2) pour prendre prise avec le chariot (A) de manière coulissante dans une paire de guides de coulissement, la paire de guides pour un premier des chariots et une paire de guides pour un second (B) des chariots étant chacune disposée sur l'une des deux faces verticales opposées d'une poutre (X) horizontale qui s'étend parallèlement aux courroies de convoyage des bandes et à angle droit par rapport à d'autres poutres (Y,Z), dans une face verticale sur laquelle la paire de guides de coulissement (1), dans laquelle un troisième (C) et quatrième (D) des chariots doivent être engagés, est disposée.

3. Appareil selon la revendication 2, caractérisé en ce que chacun des quatre chariots (A-B-C-D) est relié à une courroie crantée (3) qui est étirée entre deux poulies, l'une des dites poulies étant couplée à un arbre d'un moteur d'entraînement électrique (N), et détermine un mouvement de translation linéaire du chariot dans les deux directions.

4. Appareil selon la revendication 3, caractérisé en ce que un cylindre (4) pneumatique est supporté verticalement sur chacun des quatre chariots (A-B-C-D), une tige (5) du cylindre faisant saillie vers le bas et se terminant par un bras horizontal (6) pourvu d'une pince (7) pour saisir de manière centrale l'une des bandes pour former le cadre.

5. Appareil selon la revendication 4, caractérisé en ce que un guide (10) est fixé au cylindre pneumatique (4) et une tige (9), reliée à la tige (5) par un élément de connexion (8), peut glisser dans celui-ci, la dite tige (5) et le cylindre (4) étant mutuellement couplés de manière rigide.

6. Appareil selon la revendication 5, caractérisé en ce que le cylindre pneumatique (4) est supporté en rotation par un roulement et est couplé de manière rigide coaxialement à l'une des deux poulies qui étire une courroie (11) crantée sur laquelle un cylindre (12) agit de façon linéaire dans des directions alternatives.

7. Appareil selon la revendication 6, caractérisé en ce que un autre chariot (E) est prévu qui est symétrique en miroir identique à l'un des chariots (A-D).

8. Appareil selon la revendication 1, caractérisé en ce que les courroies de convoyage (N1-N4) acheminent les quatre bandes (L1-L2-L3-L4) jusqu'aux régions de prélèvement respectives formées par les butées (R) correspondantes qui sont ajustées selon la longueur des bandes individuelles de façon que les pinces (7) de prélèvement des chariots (A-B-C-D) puissent saisir les dites bandes exactement au centre.

9. Appareil selon la revendication 8, caractérisé en ce que les butées (R) d'une première (N1) et une seconde (N2) des courroies (N1, N2) sont fixées.

10. Appareil selon la revendication 4, caractérisé en ce que les dits chariots et les dites pinces sont contrôlés par un ordinateur électronique.

Drawing